At present, commercially available yo-yos mainly consist of the following components: as the basic composition, two rotators and a connecting shaft for connecting the two rotators; a screw hole is formed in the middle of a back side of each of the rotators, threads are provided on two ends of the connecting shaft; and the screw hole and the threads work together to assemble a complete yo-yo. Such a yo-yo can only be assembled in one way, that is, such a yo-yo has only one form with no alterability, and is thus less fun. As a result, kids are more likely to lose interest in such a yo-yo. Should the kids desire a yo-yo of another form, they would have to buy a new one. When they have a new yo-yo, the older one will likely be discarded, which is a waste of resources.